Ctatfs patfnts



INVENTOR. ROBERT H. HOLSING QMQW United States Patent ROCK DRILL BITRobert H. Holsing, Canton, Ohio, assignor to The Timken RfOgltEII:Bearing Company, Canton, Ohio, a corporation 0 10 Application March 3,1950, Serial No. 147,430

1 Claim. (Cl. 255-64) This invention relates to rock drill bits and ismore particularly directed to an integral pivotal or flexible washer forholding the bit on a polygonal sectioned drill rod.

The object of the invention is to provide a replaceable bit for rockdrills having pivotal or flexible integral griping portions thereonadapted to frictionally engage the drill rod to which they are removablysecured.

The invention consists in the provision of a rock drill bit to beinstalled on a polygonal sectioned drill rod and in which the sides ofthe drill bit are slashed or slotted to form integral pivotal orflexible washer portions there on prior to the hardening of the drillbit which also imparts spring properties to the washer portions and,upon being moved relative to the drill bit, will grip the drill rodinserted therein.

The invention also consists in the forming of integral pivotal orflexible washer portions on the collar of a rock drill bit for impartingresilient qualities to the washers while hardening the body of the bit.

The invention further consists in the parts and combinations andarrangement of parts hereinafter described and claimed.

In the drawings:

Fig. l is a side elevational view of a drill bit embodying theinvention,

Fig. 2 is a sectional view taken along the line 2-2 of Fig. 1,

Fig. 3 is an end view of a different form of the invention,

Fig. 4 is a sectional view taken substantially along the line 4-4 ofFig. 3,

Fig. 5 is a side elevational view of another modified form of theinvention; and

Fig. 6 is a sectional view taken substantially along the line 6-6 ofFig. 5.

The invention is embodied in the structure illustrated in the severalviews of the drawings in which the numeral 1 designates a drill bit bodyprovided with cutting edges 2. A bore 3 is provided in said body,thereby forming a collar portion 4 thereon. The bore is polygonal insection so that relative rotation between a similarly sectioned drillrod 5 inserted therein, is prevented.

A slot 6 is cut in the collar portion and the metal at the base of thecut is relieved by drilling a hole 7 therein. The slot is cut at anangle less than 90 to a plane through the collar portion extending atright angles to the longitudinal axis of the drill bit body. The slotextends to a point within the semi-circle of the collar portion on whichit is cut. The drill bit body is then heat treated to harden it and toimpart resilient properties to the partially severed washer portion 8which adapts it for pivotal or flexing motion relative to the bit body,the partially severed portion being bent inwardly prior to heat treatingso that the bore of the partially severed portion is not in exactalignment with the bore of the collar portion. The bore of the washerportion is relieved so that when the portion is pivoted or flexed outicewardly, it will be in substantial alignment with the bore 3. The drillrod 5 can then be inserted in the bore. The drill rod is held in thebore by reason of the fact that the inward pivoting or flexing washerportion causes a corner or curved edge thereof to frictionally engage alongitudinal corner of the drill rod and, during use, the vibratingaction of the drill rod and bit causes the said corner or edge of thewasher portion to be imbedded in the rod at the corner or cornersthereof, depending upon the shape of the drill rod. The drill rod may bewithdrawn from the bore after pivoting or flexing the washer portionoutwardly relative to the drill rod so that it will be disengagedtherefrom, which action will permit the bit and drill rod to beseparated.

Figs. 3 and 4 illustrate a construction similar to that shown in Figs. 1and 2, except that the severed portion 8 is crimped so that the slotdiverges outwardly. The bit is then heat treated for the purposes setforth above. The washer portion 8 has its bore suitably relieved so thatwhen an outward pivotal or flexing motion is imposed thereon, the drillrod 5 may be inserted in the bore. The washer portion overlies the borein the collar. After its release, a corner or gripping edge of thewasher portion engages with and imbeds itself in a corner or corners ofthe drill rod. The drill rod is removed in the same manner as describedabove. The form of bit shown in Figure 4 has a larger relief angle inits bore, this being necessary because of the outwardly diverging slot6.

The bit and rod are separated in the manner described above.

Figs. 5 and 6 illustrate a modified form of the invention in which thenumeral 9 designates a drill bit body having cutting edges 10 thereonand provided with a bore 11 of polygonal section. This bore receives asimilarly sectioned drill rod 12.

The drill rod is held in the bore by washer portions 13 formed bycutting slots 14 in the collar 15. Holes 16 are cut in the collar 15 atthe base of the slots, thus relieving the strain on the collar metalwhen washer portions 13 have pivotal or flexing motion imposed thereon.The slots 14 are cut at right angles to the longitudinal axis of thedrill bit body. The washer portions are then bent axially from the bodyfor diverging the slots outwardly and causing them to overlie the bore11. The bore of the washer portions is relieved so that a corner or edgethereof can engage and imbed itself in a corner or corners of the drillrod. Thereafter the drill bit is heat heated for hardening andsimultaneously imparting resilient properties to the washer portions.The drill rod is inserted in bore 11 after imposing an inward pivotal orflexing motion on washer portions 13. The relieved bores in the washerportions 13 and the bore in collar 15 are in substantial alignment whenthe washer portions are moved inwardly relative to the bit body. Thedrill rod is held in the bit bore by the overlaid washer edge portionsgripping said drill and vibration of the bit body and drill rod causessaid edge or corner of these portions to become imbedded in the drillrod. The drill rod and bit are separated by applying an inward force tothe washer portions, thus forcing them away from the drill rod towardthe collar of the bit body. This action re-aligns the bore in the collarand in the washer portions, thereby permitting separation of the bitbody and the drill rod.

What I claim is:

A drill bit adapted to be detachably connected to a drill rod; saiddrill bit including a body having cutting edges on its forward portionand a rearward collar portion having a drill rod receiving bore, saidcollar having a transverse narrow slit extending therethrough andpartially severing a substantial portion of the collar thereby forming aresilient collar portion, said collar portion being normally bent toprovide a bore portion normally out References Cited in the file of thispatent UNITED STATES PATENTS 5 188,055 Johnson Mar. 6, 1877 678,629Smith July 16, 1901 726,388 Wysong Apr. 28, 1903 822,313 Stevens June 5,1906 1,760,113 Brown May 27, 1930 10 4 .Noxley ..M. ..-V.- June21, .1932Hickman Nov. 15, 1932 Murphy June 24, 1941 Busse Apr. 14, 1942 Padley eta1 May 4, 1943 Gascoigne Dec. 21, 1943 Turner Aug. 22, 1950 OTHERREFERENCES Mechanical Engineers Handbook, Marks, 5th edition.

